The present invention relates to an oxygen and moisture impermeable multilayer barrier film, and to articles produced therefrom including ostomy bags, laminates for transdermal delivery of drugs, and heat sealable bags.
Plastic film laminates having oxygen and moisture vapor barrier properties are desirable for current packaging requirements, as well as for use in medical applications such as the fabrication of ostomy bags or transdermal drug delivery systems. Such films have been provided through the use of multi-ply film laminates where at least one of the plies is oxygen and moisture vapor impermeable. Typically, the films comprise chlorinated polyethylene films or plasticized polyvinyl chloride films, polyvinylidene chloride copolymer films, or multilayered structures such as ethylene vinyl acetate-polyvinylidene chloride/ethylene vinyl acetate combination films.
Several other methods for producing barrier films have been proposed. For example, Manne et al, U.S. Pat. No. 3,753,828 describes a method of preparing oxygen impermeable film packaging materials using an adhesive-containing Saran resin which is applied to one ply of a two-ply laminate and then cured. However, the process requires the addition of an adhesive and involves curing steps which require the use of a printing press or laminator.
Lustig et al, U.S. Pat. No. 4,348,437 relate to a coextruded multilayer food packaging film comprising a first layer of an ethylene vinyl acetate copolymer, a second layer comprising a polyvinylidene chloride copolymer or an ethylene vinyl alcohol copolymer, and a third layer comprising a blend of a polyurethane polymer and an ethylene vinyl acetate copolymer. However, the film does not provide other desirable physical properties such as softness and low noise characteristics which are required for ostomy applications.
Accordingly, the need still exists for multilayer barrier films which may be produced by simple and inexpensive conventional processes and for films which are impermeable to moisture and oxygen, provide odor barrier, softness, and low noise properties, and which have a heat sealable surface for forming bags or the like.